| A | B |
|---|
| biome | a group of ecosystems with similar climates and organisms |
| desert | an area that receives less than 25 centimeters of rain per year |
| tundra | an extremely cold, dry, land biome |
| freshwater biomes | ponds and lakes |
| estuary | is found where the fresh water of a river meets the salt water of the ocean |
| secondary succession | the series of changes that occur after a disturbance in an existing ecosystem |
| nodules | where bacteria live in bumps on the roots of certain plants |
| energy pyramid | shows the amount of energy that moves from one feeding level to another in a food web |
| producer level | where the most energy is available |
| food web | consists of many overlapping food chains |
| omnivore | a consumer that eats both plants and animals |
| scavenger | a carnivore that feeds on the bodies of dead organisms |
| producer | an organism that makes its own food |
| oxygen | the substance that is released during photosynthesis |
